"After six years of searching, an entomologist has concluded that three varieties of butterflies native to south Florida have become extinct, nearly doubling the number of North American butterflies known to be gone."

""These are unique butterflies to Florida. This is our biological treasure. Each unique species that we lose, we won't ever get that back again," Marc Minno, who conducted the survey for the U.S. Fish and Wildlife Service and the Florida Keys Mosquito Control District, told Reuters on Monday.

The disappearance of butterflies should serve as a warning about the degradation of south Florida's environment, he said."